Drivetrain Dummy Gear | 12mm Thru-Axle | Shockwave Parts

• Dangling chain: without axle support, the chain flops inside the frame and contacts the chainstay.
• Impossible backside cleaning: a slack chain won't rotate, so the backside of the links and the jockey wheels stay dirty no matter how hard you scrub.
• Messy storage: a bike resting on the saddle and handlebar, or hung by the rear triangle, drags the chain across the frame.
• Axle contact: without the axle seated, the chain can scrape directly against the dropout faces.

With the dummy installed, the chain stays tensioned. You can pedal normally while scrubbing, degreasing, or wiping the drivetrain. This makes it easy to clean the backside of the chain, jockey wheels, and derailleur cage, which is almost impossible when the chain is loose.

You clean faster, more thoroughly, and without fighting the drivetrain the whole time.

Perfect when the wheel is off for a while. On a repair stand or resting on the saddle and handlebar, the drivetrain stays tidy. The chain stays where it belongs instead of dragging across the frame or hanging awkwardly.

You can rotate the cranks and shift through gears even without the rear wheel. This is ideal for checking derailleur alignment, cable tension, or shifter function during maintenance without reinstalling the wheel.

Designed for 12 mm rear thru-axlesthe current standard on modern MTB frames. Slide it in where the wheel axle sits, snug it down, and the drivetrain is ready to use. Removal is just as fast.

Any time the rear wheel comes off, for a tire swap, a brake bleed, or a full drivetrain clean, the Drivetrain Dummy goes in before the wheel goes out. The chain stays tensioned on a 12 mm thru-axle body, the derailleur holds its position, and the cranks keep turning. You stop managing the chain and start doing the actual work.